Offers that are easy to understand are easy to buy. It might seem like common sense, but most people overcomplicate their products and offers. When an offer is easy to understand, it becomes easier to buy because of a psychological concept called Cognitive Fluency. Cognitive Fluency says that the easier it is for our brains to understand something, the more persuasive and engaging it is. Here's how Apple, McDonald's, and Dropbox do it - and how you can do it, too no matter the size of your...